Technical Field
Exemplary aspects of the present invention relate to a fixing device that fixes a toner image on a recording medium, and an image forming apparatus including the fixing device.
Related Art
In related-art image forming apparatuses, a surface of a fixing belt as a fixing member in a fixing device is rubbed and polished to maintain a surface of the fixing member in optimum condition of the fixing member, thus preventing generation of a poor-quality image having streaks caused by an edge of a sheet (a recording medium) conveyed by the fixing member.
To eliminate glossy streaks caused by the sheet edge, it is desired that the surface of the fixing belt should be aggressively abraded to make the entire surface of the fixing belt rough. A roller with a surface that has a polishing function is often used as a member for rubbing and polishing the surface of the fixing belt. In this patent specification, such a roller is called “a polishing roller”.
An electrophotographic image forming apparatus includes a fixing device that fixes a toner image on a recording medium. In the fixing device, the recording medium bearing an unfixed toner image passes a fixing nip between a fixing member and a pressure member, so that the toner image is fixed on the recording medium with heat and pressure. When this type of the fixing device feeds a recording medium having a predetermined width, an edge of the recording medium passes a certain area. Accordingly, as long as the recording media have substantially the same size, the edge of each recording medium passes the same area of the fixing member. Moreover, an edge of a sheet includes a burr that is generated when the sheet is cut. The sheet edges including the burrs also pass the same area of the fixing member. Consequently, the fixing member has a surface including the area through which the sheet edges including the burrs pass, and such an area of the surface becomes rough, causing unevenness and streaks in an image and degrading image quality.